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The objective of this study was to carry out a taxonomic review of fossil American phlebotomine sand flies and describe two new species found in amber in the Dominican Republic. The gonostyle of one of these, Micropygomyia dorafeliciangeliae nov. sp., (=Lutzomyia dorafeliciangeliae, species group oswaldoi), has five spines, similar to that of Micropygomyia paterna (Quate, 1963) (= Lutzomyia paterna, species group oswaldoi), but they may be distinguished by the alpha/gamma ratio, which is <1.0 in the new species and >1 in the latter. Pintomyia dominicana nov. sp. (=Lutzomyia dominicana, species group verrucarum) has four spines on the gonostyle and presents a long bristle on the apex of the paramere, which distinguishes it from the other fossil species. With the description of these two new species, a total of 14 species of the American fossil phlebotomine sand flies has been described, 10 of which belong to the genus Pintomyia. An identification key for male fossil species is presented.

Ochlerotatus albifasciatus (Macquart) (Diptera: Culicidae) is a mosquito species of medical and veterinary importance, usually associated with temporary groundwater habitats. Eggs obtained from females collected in Córdoba city, in the center of Argentina, were studied using scanning electron microscopy. The eggs are elliptical in outline, measuring ≈615.7 ± 37.24 µm in length (1) and 180.7 ± 22.87 µm in width (w), with an egg index (l/w ratio) of 2.9–3.7. The outer chorionic sculpture has racquet-shaped and wristwatch-shaped cells consisting of a small central tubercle surrounded by larger tubercles and followed by a row of smaller tubercles on one or both sides, respectively, although variations between regions of the egg were observed. The micropylar apparatus has a collar with evident molding and edges of determined length, albeit irregular, with defined margins for the transition area and a thickness of ≈10.7 µm. The margins of the micropylar disc are raised and the disc measures ≈21.1 µm in diameter. The micropyle is distinct.

During a distribution survey of flies of medical importance around northern Thailand, we discovered two new species of flesh fly Sarcophaga (s. lat.) (Diptera: Sarcophagidae) that also are new to science. The species are Sarcophaga nanensis sp. nov. and Sarcophaga kiyokoae sp. nov. Adults of the former species was recovered from Pua River of Nan province (19° 12′29″ N, 100° 56′ 36″ E) 442 m in northern Thailand, whereas the latter species was collected around Kuang River (19° 0′3″ N, 99° 17′6″ E) 551 m of the lowland forests of Chiang Mai province, northern Thailand. Although these two sarcophagid flies showed similarity in their male terminalia in having large aedeagi and rounded juxta, illustrations of the sternite 5, cercus, surstylus, and anterolateral margin of the aedeagus allow differentiation between them. A key is provided to the adult males of the flesh flies of medical importance in Thailand.

Wing geometric morphometry of Triatoma infestans (Klug) (Hemiptera: Reduviidae) populations in northwestern Argentina showed that individual collection sites represent the discrete unit where metric differentiation took place. Here we studied temporal variations in wing size and shape of T. infestans populations from defined capture sites on three occasions between 2000 and 2003. Bugs collected from domiciles and/or storerooms had significantly larger right-wing centroid size than bugs collected at goat and/or pig corrals by the end of summer 2000 for both sexes. Conversely, male bugs collected from domiciles and/or storerooms had significantly smaller centroid size than bugs collected from pig corrals in spring 2002. The inversion in wing centroid size between seasons was consistent between sexes. Wing shape analysis from the south-central extreme of the study village showed divergence between collection dates for both sexes. Wing shape divergence was highly significant between male bugs collected by the end of summer 2000 and those collected in spring 2002 and by the end of summer 2003. For females, wing shape divergence was marginally significant between the end of summer 2000 and spring 2002, and significant between spring 2002 and the end of summer 2003. Unlike season-related variations in wing centroid size, shape differentiation was related to the time period elapsed between sample collections and suggested genetic influences acting on shape. Simultaneous consideration of wing size and shape provided complementary information on the direction and timing of bug dispersal. Morphological studies may allow determining the degree of relatedness of different bug populations and to associate morphological heterogeneity with temporal patterns of reinfestation.

Dengue dynamics in Rio de Janeiro, Brazil, as in many dengue-endemic regions of the world, is seasonal, with peaks during the wet-hot months. This temporal pattern is generally attributed to the dynamics of its mosquito vector Aedes aegypti (L.). The objectives of this study were to characterize the temporal pattern of Ae. aegypti population dynamics in three neighborhoods of Rio de Janeiro and its association with local meteorological variables; and to compare positivity and density indices obtained with ovitraps and MosquiTraps. The three neighborhoods are distinct in vegetation coverage, sanitation, water supply, and urbanization. Mosquito sampling was carried out weekly, from September 2006 to March 2008, a period during which large dengue epidemics occurred in the city. Our results show peaks of oviposition in early summer 2007 and late summer 2008, detected by both traps. The ovitrap provided a more sensitive index than MosquiTrap. The MosquiTrap detection threshold showed high variation among areas, corresponding to a mean egg density of ≈25–52 eggs per ovitrap. Both temperature and rainfall were significantly related to Ae. aegypti indices at a short (1 wk) time lag. Our results suggest that mean weekly temperature above 22–24°C is strongly associated with high Ae. aegypti abundance and consequently with an increased risk of dengue transmission. Understanding the effects of meteorological variables on Ae. aegypti population dynamics will help to target control measures at the times when vector populations are greatest, contributing to the development of climate-based control and surveillance measures for dengue fever in a hyperendemic area.

The bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), occurs in aggregations until the conditions are no longer beneficial, leading to dispersal. Active and passive bed bug dispersal causes migrations from main aggregations either within a room, from room to room within a building, or from building to building. Because bed bug movement is an important factor in the spread of infestations, we wanted to determine how population structure and size affect bed bug aggregations. Engorged bed bugs were placed in glass petri dish arenas at varying densities, sex ratios, and population compositions. Nymphs had a high tendency to aggregate, varying between 94 and 98%, and therefore were not the likely dispersal stage of the bed bug. At densities of 10 and 40 adults at a 1:1 sex ratio, there were significantly more lone females than lone males. When the population composition was varied, the percentage of lone females was significantly higher than that of males and nymphs at population compositions of 40 and 80% adults. When the sex ratio of adults was varied, there were significantly more lone females than males in arenas with 20, 50, and 80% males. Females, being found away from aggregations significantly more often than any other life stage, are potentially the dispersal stage of the bed bug. Active female dispersal away from main aggregations can potentially lead to treatment failures and should be taken into account when using control methods.

Triatoma infestans Klug is dimorphic for flight muscles. This dimorphism may affect flight dispersal, reinfestation patterns, and transmission risk. To understand the contributions of genes and environment to morph determination, it is first necessary to characterize the temporal dynamics of flight muscle development. Field-collected T. infestans adults were dissected 20 or 100 d after collection, and those collected as nymphs were dissected at ≈4, 15, or 44 d after the imaginal molt. The occurrence of flight muscles was additionally assessed by minimally invasive, repeated observations through the scutum of live bugs. Overall, 33.5% of 179 males and 7.8% of 179 females had no flight muscles. Neither dissections nor repeated observations evidenced changes in morph type during adult life, suggesting that the occurrence of flight muscles is mostly irreversible within the time span of observations and is determined before or during final ecdysis. Flight muscles were detectable at 4 d after emergence and achieved complete development within 4–15 d after emergence. The repeated observation of thoracic contents through the scutum showed very high sensitivity and specificity and apparently had minor effects on mortality. In another bug population located 360 km away, 16.4% of 177 males and 6.7% of 149 females had no flight muscles. Current results show that the sex-biased flight muscle dimorphism is a regionally widespread character in T. infestans. This character should be considered in field population studies that seek to measure reinfestation risk and dispersal in T. infestans and other Triatominae.

Populations of Ixodes scapularis Say nymphs were surveyed at a Lyme disease—endemic area for 8 consecutive yr (1998–2005) to characterize annual changes in abundance. Precipitation and temperature were also monitored over the period 1998–2004 to determine their potential value as predictors of tick abundance. Although both parameters showed annual variation, no statistical differences in the annual abundance of I. scapularis nymphs were observed over the 8-yr period. Our results suggest that precipitation and temperature were not predictive of the abundance of I. scapularis nymphs.

The increasingly widespread use of prescribed burns to manage oak (Quercus spp.)-hickory (Carya spp.) forests in the Missouri Ozarks, USA, has considerable potential to alter the abundance of Amblyomma americanum (L.) (Acari: Ixodidae), the lone star tick, an important vector of several emerging pathogens. In particular, responses of important tick hosts, primarily white-tailed deer (Odocoileus virginianus), to fire management and the resultant changes in the distribution and abundance of A. americanum are largely unknown. Using several large burn units (61–242 ha) within the Ozark ecosystem, I measured the effect of the time elapsed since sites were burned on the density of white-tailed deer and the larval life stage of A. americanum. Larval tick densities were highest in areas that were 2 yr postburn and were >6 times higher than tick densities in control units. Deer densities were highest in sites that were burned in the same year as this study and decreased significantly with time since burn. These results suggest that intensive use of postburn sites by white-tailed deer may increase the abundance of A. americanum to levels greater than occurs in sites that remain unburned. Thus, fire management, although beneficial in many aspects of ecosystem management, may bear the unintended cost of locally increasing abundance of A. americanum.

The importance of predation as a mortality factor in adult mosquitoes has received only limited attention in the scientific literature. Despite the lack of consensus among researchers as to whether bats are important predators of mosquitoes, there have been no attempts to directly document the effect of bats on mosquito populations or behavior. We conducted an enclosure experiment to test the hypothesis that bats reduce the local abundance of ovipositing female mosquitoes by examining whether the northern long-eared bat (Myotis septentrionalis Trouessart) had an effect on Culex spp. (Diptera: Culicidae) oviposition, using naturally occurring mosquitoes, either through direct predation or trait mediated effects on mosquito behavior. We found a significant, 32% reduction in egg-laying activity associated with bat predation. Artificial oviposition habitats directly outside bat enclosures experienced no reduction in oviposition; we attributed the observed reduction in egg-laying activity to direct predation on ovipositing females by bats and not changes in mosquito behavior. In addition, we noted a decrease in the number of larval mosquitoes in enclosures exposed to bat predation. These results suggest the impact of aerial predators on pathogen transmission may be large, and warrants further scientific investigation.

The host feeding of Anopheles minimus Theobald and An. fluviatilis James was studied in the villages of east-central India by conducting human landing collections between 1800 and 0600 hours at monthly intervals from May 2006 to July 2007. Four species of anopheline mosquitoes, An. minimus, An. fluviatilis, An. maculatus Theobald, and An. subpictus Grassi, were collected, the former two known vector species of malaria being the most abundant (97.1%). The An. minimus complex has been identified as sibling species A and An. fluviatilis complex as species S (90.9%) and T (9.1%). Both the species were prevalent throughout the year and obtained from landing collections indoors and outdoors. The average human landing density (HLD) of An. minimus and An. fluviatilis was 1.76 and 1.78 indoors and 1.71 and 1.56 per human per night outdoors, respectively. The HLD was relatively higher during the rainy season, although not significant in the case of An. fluviatilis. The human landing activity of An. minimus and An. fluviatilis occurred between 2000 and 0400 hours and peaked during 2300–0200 hours both indoors and outdoors.

Mosquito Magnet-X traps were modified for use with blue, green, red, and blue-green-red light-emitting diodes and olfactory attractants to determine the response of Lutzomyia shannoni (Dyar) and Lutzomyia vexator (Coquillett) (Diptera: Psychodidae) field populations to these attractants. Red and blue-green-red-baited traps captured the highest numbers of Lu. shannoni and Lu. vexator, respectively, although, there were no significant differences between the colors. Baiting the traps with CO2 attracted significantly higher numbers of Lu. shannoni but showed no effect on Lu. vexator capture. In comparison with CO2 alone, Lu. shannoni preferred 1-octen-3-ol and 1-hexen-3-ol (0.05 g per trap) in combination with CO2.

The “kissing bugs,” Triatoma dimidiata (Latreille) and Bhodnius prolixus (Stål) (Reduviidae: Triatominae) are major vectors of Chagas disease in Central and South America. To further uncover the attraction to certain host cues by these vectors at long and short distances from their host, the behavioral responses of two life stages (fifth-instar nymphs and adult males) of these two species to different known or suspected attractants, alone or in combination, were investigated. Tests were done using short- and long-range environments, namely, a four-port olfactometer and a long-range artificial chamber designed to mimic the insect's natural habitats. In single-attractant trials, heat alone and CO2 alone were found to be more attractive than selected chemicals. In multiple-attractant trials, both species and life stages were attracted at short distances, and a statistically significant synergistic increase in attraction was observed in long-distance multimodal tests. Lures containing CO2 were the most effective attractants at both long and short distances. R. prolixus adult males were significantly less attracted to several lure combinations than the nymphs of either species, perhaps because adults were more motivated to seek mates than feed. Our findings suggest that although the triatomine bugs may be capable of detecting odorants and heat sources at short distances, their ability to locate a host over a long distance is best aided by the presence of a CO2 plume.

The distribution of Aedes aegypti (L.) in Australia is currently restricted to northern Queensland, but it has been more extensive in the past. In this study, we evaluate the genetic structure of Ae. aegypti populations in Australia and Vietnam and consider genetic differentiation between mosquitoes from these areas and those from a population in Thailand. Six microsatellites and two exon primed intron crossing markers were used to assess isolation by distance across all populations and also within the Australian sample. Investigations of founder effects, amount of molecular variation between and within regions and comparison of FST values among Australian and Vietnamese populations were made to assess the scale of movement of Ae. aegypti. Genetic control methods are under development for mosquito vector populations including the dengue vector Ae. aegypti. The success of these control methods will depend on the population structure of the target species including population size and rates of movement among populations. Releases of modified mosquitoes could target local populations that show a high degree of isolation from surrounding populations, potentially allowing new variants to become established in one region with eventual dispersal to other regions.

The current study aimed to provide further evidence on the status of species composition, insecticide resistance, and vectorial capacity within the members of Anopheles (Anopheles) Hyrcanus Group in Ardebil, Giulan, and Khuzestan provinces of Iran. Sequencing the internal transcribed spacer 2 (ITS2) of ribosomal DNA gene led to identification of two members of Hyrcanus complex: Anopheles hyrcanus Pallas and a new species/form, hereafter called Anopheles hyrcanus spIR as a world record. Furthermore, we identified and compared partial sequences of exons I and II and the whole intron I region of insecticide resistance-related voltage-gated sodium channel (vgsc) gene in populations of Hyrcanus Group and other main old world Anopheles species. The ITS2 and vgsc sequences in members of Hyrcanus Group and other Anopheles species were used for construction of phylogenetic tree, which demonstrated the evolutionary relatedness among Western and Eastern Palearctic taxa within the Hyrcanus Group. A nested polymerase chain reaction assay for detection of Plasmodium species revealed the infection of Plasmodium falciparum within An. hyrcanus collected from Fooman district in Guilan province. The data from this study led to the introduction of a new member/form within the Hyrcanus Group, identification and definition of the status of knockdown resistance related to pyrethroids and DDT in their vgsc gene, detection of Plasmodium infection, and further evidence on genetic relatedness within these taxa. The overall results may suggest reconsidering the role of An. hyrcanus in malaria transmission, which would be useful for implementation and evaluation of malaria control programs in Western Palearctic region.

Visceral leishmaniasis is caused by Leishmania infantum, which is transmitted to humans by bites of phlebotomine sand flies and is one of the most important public health problems in Iran. To identify the vector (s), an investigation was carried out in Germi district, an important focus of the disease in Ardebil province in northwestern Iran, during July-September 2004 and 2005. Using sticky papers, CDC light traps and aspirators, 3,560 sand flies were collected and identified to species. Host bloodmeal preference and Leishmania infections in female specimens were evaluated using enzymelinked immunosorbent assay (ELISA) for the former and microscopic examination followed by polymerase chain reaction (PCR) assay using species-specific kinetoplast minicircle primers for the latter. Nine sand fly species are present in the district, including Phlebotomus kandelakii Shchurenkova, Phlebotomus perfiliewi transcaucasicus Perfil'ev, Phlebotomus major Annandale, Phlebotomus balcanicus Theodor, Phlebotomus halepensis Theodor, Phlebotomus brevis Theodor & Meshghali, Phlebotomus papatasi Scopoli, Sergentomyia dentata Sinton, and Sergentomyia sintoni Pringle, with P. p. transcaucasicus being the most prevalent representative of the genus Phlebotomus at 45%. The anthropophilic index for P. p. transcaucasicus was 36.3%, indicating a strong preference for humans. Of 905 female P. p. transcuacasicus dissected, 10 (1.1%) were found naturally infected with promastigotes. Species-specific amplification of promastigotes eluted from Giemsa-stained slides revealed specific PCR products of L. infantum DNA. Based on its high anthropophily and natural infections with L. infantum, and the fact that it was the only species found infected with L. infantum, we conclude that P. p. transcaucasicus is the principal vector of L. infantum in northwestern Iran.

We determined nucleotide sequences of the nuclear rDNA internal transcribed spacer (ITS)1–5.8S-ITS2a-2S-ITS2 region in 103 individuals of 25 Culicoides species (Diptera: Ceratopogonidae) from 11 locations in Japan. Ribosomal RNA genes, 5.8S and 2S rDNA, were highly conserved among the species with few variations. The ITS2a region showed length variation among species. Both ITS1 and ITS2 showed highly varied sequences among species. The noticeable indel regions among ITS1 sequences are present in some Culicoides species, separating species into two types having long or short ITS1 region. However, Culicoides cylindratus Kitaoka possesses both types of ITS1 in each individual; these results seem to indicate that the ITS1-long type was the prototype and the short type was produced through deletion in many Culicoides species. One species, belonging to subgenus Avaritia, possessed an Avaritia-specific sequence in ITS1 and phylogenetically formed a monophyletic group. Geographical genotypes in a species were not clear. Species-specific sequence features were observed, enabling molecular identification of Culicoides species.

We used an expressed sequence tag and 454 pyrosequencing approach to initiate a study of the genome of the screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae). Two normalized cDNA libraries were constructed from RNA isolated from embryos and second instar larvae from the Panama 95 strain. Approximately 5,400 clones from each library were sequenced from both the 5′ and 3′ directions using the Sanger method. In addition, double-stranded cDNA was prepared from random-primed polyA RNA purified from embryos, second-instar larvae, adult males, and adult females. These four cDNA samples were used for 454 pyrosequencing that produced ≈300,000 independent sequences. Sequences were assembled into a database of assembled contigs and singletons and used to search public protein databases and annotate the sequences. The full database consists of 6,076 contigs and 58,221 singletons assembled from both the traditional expressed sequence tag (EST) and 454 sequences. Annotation of the data led to the identification of several gene coding regions with possible roles in sex determination in the screwworm. This database will facilitate the design of microarray and other experiments to study screwworm gene expression on a larger scale than previously possible.

Mouse-baited traps were used to assess the longevity and dispersal of male and female Aedes albopictus by mark-release-recapture at two sites on La Réunion Island. Recapture rate was high, and mosquitoes of both sexes appeared up to 23 d after release. A daily survival probability of ≈0.95 for males and females, far higher than expected, was estimated from these results. There was evidence that both sexes prefer to follow corridors of vegetation rather than crossing open spaces. Populations of wild mosquitoes had parous and insemination rates indicative of a young population. These results are relevant to future attempts to control this species by sterile insect technology.

This no-choice, laboratory study focuses on the feeding of dried, ground, homogeneous powdered, unprocessed fruit and leaves of Azadirachta indica and Melia azedarach to Lutzomyia longipalpis larvae to determine the effects on their mortality and metamorphosis. A. indica and M. azedarach fruit and leaves significantly increased larval mortality in comparison to larvae fed the untreated, standard diet. A. indica fruit and leaves blocked the molting of the larvae to the fourth instar, resulting in them remaining as third instars until the end of the experiment. M. azedarach fruit also blocked the molting of larvae, which remained permanently in the fourth instar. Feeding M. azedarach leaves resulted in greater molt inhibition. All insects in this group stopped their development as second-instar larvae. No antifeedant effect was detected for any experimental treatment. The results indicate that nontoxic, unprocessed materials obtained from A. indica and M. azedarach are potent development inhibitors of L. longipalpis larvae.

The purpose of this study was to evaluate the use of rhodamine B as an orally delivered biomarker for rodents and a feed-through transtadial biomarker for phlebotomine sand flies (Diptera: Psychodidae ). Rhodamine B-treated hamsters were visibly marked for up to 8 wk, and their feces were fluorescent when examined under a fluorescence microscope. The development and survival of sand fly larvae fed feces of rhodamine B-treated hamsters were not significantly different from control sand flies. Adult male and female sand flies, that had been fed as larvae the feces of rhodamine B-treated hamsters, were fluorescent when examined using fluorescent microscopy and could be distinguished from control sand flies. Adult female sand flies that took bloodmeals from rhodamine B-treated hamsters were fluorescent when examined immediately after feeding. Rhodamine B incorporated rodent baits could be used to detect adult male and female sand flies that fed on the feces of baited rodents as larvae, or adult female sand flies that have taken a bloodmeal from bait-fed rodents. This would allow the delineation of specific foci with rodent-sand fly associations that would be susceptible to control by using feed-through or systemic insecticides.

Prescribed fire was investigated as a method for controlling ixodid and argasid ticks in chaparral habitats in northern California. Two experimental and two adjacent control plots within a wildlife preserve were monitored for 1 yr postburn. Ticks were collected by flagging vegetation, by CO2-baited pitfall trap, and by live-trapping rodents. Twice as many rodents were caught at control sites compared with burn sites and no dusky-footed woodrats, Neotoma fuscipes Baird, were found in the treatment sites postburn. This species is known to be a reservoir of the agents of Lyme disease, Borrelia burgdorferi sensu stricto Johnson, Schmid, Hyde, Steigerwalt & Brenner, and human granulocytic anaplasmosis, Anaplasma phagocytophilum Dumler, Barbet, Bekker, Dasch, Palmer, Ray, Rikihisa, Rurangirwa. Six ixodid tick species were removed from rodents (Ixodes pacificus Cooley & Kohls, Ixodes jellisoni Cooley & Kohls, Ixodes spinipalpis Hadwen & Nuttall, Ixodes woodi Bishopp, Dermacentor occidentalis Marx, and Dermacentor parumapertus Neumann), two of which transmit bacterial zoonotic agents to people in the far-western United States. There was no decrease in number of ticks per animal trapped at either burn site compared with controls; in fact, the mean number of immature I. pacificus per rodent was significantly higher at one burn site than its control site. Soil refugia may protect ticks from fire-induced mortality; the argasid tick Ornithodoros coriaceus Koch, which lives in soil, was unaffected by the prescribed fire as were I. pacificus and D. occidentalis buried in packets 2.5 cm below ground. We conclude that although prescribed fires in chaparral habitats may diminish local rodent abundance, it does not decrease tick loads on rodents. Furthermore, burning chaparral does not result in a decreased abundance of adult ixodid ticks on vegetation and apparently does not affect argasid or ixodid ticks that are sheltered within soil refugia.

We collected 379 samples of eight flea species from 235 specimens of wild mammals captured in three areas of the Central Atlantic Forest Corridor in the state of Espirito Santo, southeastern Brazil, between August 2006 and February 2008. Among the 22 mammal species, we found eight species of marsupials (order Didelphimorphia), 13 species of rodents (order Rodentia), and one species of wild cat (order Carnivora). The total prevalence of infestation was 28.1%, with similar percentages in rodents (26.4%) and marsupials (29.5%). The infestation in the southern area was 3 times higher than that observed in the northern area. The infestation by single flea species was >6 times higher than the total number of double and triple infestations. The mean abundance of fleas was 1.61. The flea female/male ratio was 1.38, ranging from 0.95 in Adoratopsylla (Tritopsylla) intermedia intermedia (Wagner) to 1.81 in Hechtiella nitidus (Johnson) in the most flea species infested. We report three new records of flea species in the state of Espírito Santo, and eight new host records.

The mating efficiencies (the percentage of females inseminated by males) of fieldcollected and laboratory-colonized Aedes triseriatus (Say) (Diptera: Culicidae) female mosquitoes transovarially infected or uninfected with La Crosse virus (LACV) were compared. The females were placed in cages with age-matched males, and the insemination rates (number of inseminated females of the total number of females examined) were determined daily by detection of sperm in the spermathecae. LACV-infected mosquitoes typically mated earlier than uninfected mosquitoes, i.e., insemination occurred earlier after the mixing of males and females. LACV load was not correlated with increased insemination.

Natural infections with Leishmania were found in females of the phlebotomine sand flies Lutzomyia neivai (Pinto) (=Nyssomyia neivai) and Lutzomyia sallesi (Galvão & Coutinho) (=Evandromyia sallesi) (Diptera: Psychodidae) from Lassance, in the Brazilian state of Minas Gerais. Promastigotes were found in the pyloric region of the former species and in the abdominal midgut of the latter species. Insects found to be infected by microscopic examination were macerated in saline solution and inoculated into hamsters. Subsequent analysis by polymerase chain reaction-restriction fragment length polymorphism revealed both isolates to belong to the species Leishmania infantum chagasi Cunha & Chagas.

In the current study, samples of 50 synanthropic flies were collected from each of five rural locations used for domestic animal husbandry (specifically a cattle barn, a dog pound, a horse stable, and a pigpen). Flies were examined using a variety of microbiological methods to determine the pathogenic agents that they carried. The most frequently sampled species were Musca domestica (L.) (51%) followed by Stomoxys calcitrans (L.) (24%). All fly species were found to carry an array of different pathogenic bacterial and fungal species. Among these were human pathogens such as Campylobacter jejuni and Escherichia coli-strains (EHEC, EPEC, and ETEC) and the fungi Candida albicans and Candida tropicalis. The germs could be detected in the intestines as well as on the exoskeletons of the flies. The current study confirms and supplements the general knowledge about pathogens that may be transmitted to domestic animals and humans by synanthropic flies.

A double-antibody enzyme-linked immunosorbent assay was used to determine the bloodmeal sources of adult mosquitoes (Diptera: Culicidae) collected in encephalitis vector surveillance mosquito traps in Western Australia between May 1993 and August 2004. In total, 2,606 blood-fed mosquitoes, representing 29 mosquito species, were tested, and 81.7% reacted with one or more of the primary antibodies. Aedes camptorhynchus (Thomson) and Culex annulirostris Skuse were the most common species tested, making up 47.2% (1,234) and 35.6% (930), respectively. These species obtained bloodmeals from a variety of vertebrate hosts but particularly marsupials and cows. In contrast, Culex pullus Theobald (72.7%; 24/33), Culiseta atra (Lee) (70.0%; 7/10), Culex globocoxitus Dobrotworsky (54.5%; 12/22), and Culex quinquefasciatus Say (39.3%; 22/56) often obtained bloodmeals from birds. Although Ae. camptorhynchus and Cx. annulirostris are well established vectors of arboviruses, other mosquitoes also may have a role in enzootic and/or epizootic transmission.

A citywide control program of Aedes aegypti (L.) (Diptera: Culicidae) mainly based on the use of larvicides reduced infestations but failed to achieve the desired target levels in Clorinda, northeastern Argentina, over 5 yr of interventions. To understand the underlying causes of persistent infestations and to develop new control tactics adapted to the local context, we conducted two pupal surveys in a large neighborhood with ≈2,500 houses and recorded several variables for every container inspected in fall and spring 2007. In total, 4,076 lots and 4,267 containers were inspected over both surveys, and 8,391 Ae. aegypti pupae were collected. Large tanks used for potable water storage were the most abundant and the most productive type of container, accounting for 65–84% of all the pupae collected. Therefore, large tanks were key containers and candidates for improved targeted interventions. Multivariate analysis showed that containers located in the yard, at low sun exposure, unlidded, filled with rain water, and holding polluted water were all more likely to be infested by larvae or pupae. When only infested containers were considered, productivity of pupae was most closely associated with large tanks and rain water. A stochastic simulation model was developed to calculate the expected correlations between pupal and Stegomyia indices according to the characteristics of the distribution of larvae and pupae per container and the spatial scale at which the indices were computed. The correlation between pupal and Stegomyia indices is expected to increase as infestation levels decline.

Data from a 4-yr study of phlebotomine sand flies in 44 stations in southwestern Morocco are presented. Correspondence analysis is used to describe the habitat preferences of nine sand fly species on a meso-scale (station) and a micro-scale (biotope). This work, based on highly diversified data from various stations, comprising several biotopes sampled during different seasons, provides new information on the ecology of sand flies in southwestern Morocco. It highlights many natural and artificial factors that affect the abundance and distribution of sand fly populations. The impact of climate, urbanization, proximity of humans and domestic animals, organic matter in the soil, shelter, and vegetation type is discussed.

Triatoma infestans (Klug), the most important vector of Chagas disease in southern South America, is a highly domiciliated species with well-known sylvatic foci only in the Bolivian Andean valleys and in the Bolivian Chaco, where melanic insects designated as “dark morphs” were found. After the tentative identification of two melanic bugs collected from parrot nests in a forest reserve in the Argentine Chaco as T. infestans, we conducted an intensive search there using mouse-baited sticky traps in summer 2006 and 2007. Four live T. infestans bugs were collected in trees without parrot nests in 288 trap-nights, whereas no bug was collected from inside trees with active parrot nests in 51 trap-nights. To increase bug captures, hollow tree trunks that recently had had Amazona aestiva (Berlepsch) and Aratinga acuticaudata (Vieillot) parrot nests were treated with insecticide fumigant canisters exhibiting strong knockdown power. Four (22%) of 18 trees were positive for T. infestans with a dark phenotype. A fragment of the mitochondrial gene COI of 8 of the 14 triatomine bugs collected was successfully sequenced and confirmed as T. infestans. Most of the bugs were captured from Aspidosperma quebracho-blanco (Schlechter) hollow tree trunks harboring parrot nests. All of the T. infestans collected from the nearest house located at 10 km from the sylvatic foci displayed normal chromatic characters. The repeated finding of T. infestans in sylvatic habitats, albeit at very low density, shows that this species is capable of maintaining viable sylvatic foci in the absence of human hosts and immigration from domestic populations. These are the first confirmed findings of sylvatic T. infestans colonies in Argentina and of dark morphs in the Argentine Chaco.

Multiple isolates of an alphaviruses within the western equine encephalomyelitis-serocomplex that were related closely to Ft. Morgan and its variant Buggy Creek virus were made from swallow bugs, Oeciacus vicarius Horvath (Hemiptera: Cimicidae), collected from cliff swallow (Petrochelidon pyrrhonota) nests at the Stone Lakes National Wildlife Refuge, Sacramento County, CA, during the summers of 2005 and 2006. This virus (hereafter Stone Lakes virus, family Togaviridae, genus Alphavirus, STLV) was the first record of this viral group west of the Continental Divide. STLV replicated well in Vero and other vertebrate cell cultures but failed to replicate in C6/36 cells or infect Culex tarsalis Coquillett mosquitoes. STLV failed to produce elevated viremias in adult chickens or house sparrows and was weakly immunogenic. In addition, STLV was not isolated from cliff swallow nestlings nor was antibody detected in adults collected at mist nets. We suggest that STL and related swallow bug viruses may be primarily infections of cimicids that are maintained and amplified either by vertical or nonviremic transmission and that cliff swallows may primarily be important as a bloodmeal source for the bugs rather than as an amplification host for the viruses.

A 2-yr survey of hymenopteran parasitoids associated with carrion-breeding flies was conducted to establish the parasitoid species of potential forensic significance in Western Australia. Host associations, seasonality, and rates of parasitism in the field were examined to assess the value of the identified parasitoids as forensic indicators of time since death. Four species of parasitoid emerged from dipteran specimens collected from carcasses: Tachinaephagus zealandicus Ashmead (Encryptidae), Nasonia vitripennis Walker (Pteromalidae), Spilomicrus sp. (Diapriidae), and Aphaereta sp. (Braconidae). Overall parasitism of carrion-breeding flies was 11.8%. T. zealandicus and N. vitripennis were the predominant species, accounting for 86.3 and 11.5% of parasitism observed, respectively. In contrast, Aphaereta sp. and Spilomicrus sp. were intermittently collected from carcasses throughout the study and the parasitism rates of both species were low (≤3.0%). Our findings provide forensically important biological and behavioral data of parasitoid—host interactions within carcass environments. The cosmopolitan parasitoids T. zealandicus and N. vitripennis have the greatest potential as indicators of time since death in forensic investigations based on their broad host ranges, rates of parasitism, and seasonal prevalence. In combination, these two species are present throughout the year and they parasitized nearly all of the dipteran species that colonize carcasses. Because both are cosmopolitan species, the data presented here are applicable to regions experiencing a similar Mediterranean climate. This work reports the first incidence of T. zealandicus and N. vitripennis parasitizing the dipteran species Calliphora albifrontalis Malloch (Calliphoridae), Calliphora dubia Macquart (Calliphoridae), and Hydrotaea rostrata Robineau-Desvoidy (Muscidae).

The Asian tiger mosquito Aedes albopictus (Skuse) was first detected in New Jersey in 1995 during mosquito surveillance operations in Monmouth County. We tracked statewide changes in populations of the Asian tiger mosquito and its association with West Nile virus from 2003 to 2007. Ae. albopictus population abundance has increased in New Jersey since 2003, primarily along the urban corridor between New York City and Philadelphia, and they are now expanding their range further into suburban and rural areas of the state. Ae. albopictus has invaded all counties of New Jersey except for two northwest rural counties (Sussex and Warren). West Nile virus was detected in Ae. albopictus throughout several foci in New Jersey during the study, underscoring the public health significance of this mosquito.

Brazil has the third richest bird diversity of the world; however, there are few data concerning ticks (Acari: Ixodidae) parazitizing birds. The aim of the study was to report tick infestations on wild birds from an Atlantic rain forest region of Brazil. During 2 yr, ticks were collected from birds and from the environment in 12 forest sites. A total of 1,725 birds were captured representing 80 species from 24 families. In total, 223 (13%) birds were found infested by immature stages of Amblyomma ticks: 1,800 larvae and 539 nymphs. The prevalence of ticks was higher among birds from the families Thamnophilidae, Conopophagidae, and Momotidae. The most common tick parasitizing birds was Amblyomma nodosum Koch. Other tick species, Amblyomma coelebs Neumann, Amblyomma cajennense (F.), Amblyomma ovale Koch, Amblyomma longirostre (Koch), Amblyomma calcaratum Neumann, and Amblyomma naponense (Packard), were found sporadically. Among freeliving ticks collected in the environment, A. cajennense was the most common, followed by A. coelebs, A. naponense, Amblyomma brasilense Aragão, and Hemaphysalis juxtakochi Cooley.

Bloodmeal identification and the detection of avian malaria parasite from mosquitoes (Diptera: Culicidae) were carried out by polymerase chain reaction-based methods for field samples collected in coastal areas of Tokyo Bay, Japan, from April to October 2007. The following seven mosquito species were collected: Aedes albopictus (Skuse), Culex pipiens pollens Coquillett, Culex pipiens form molestus Forskal, Culex tritaeniorhynchus Giles, Culex inatomii Kamimura & Wada, Culex bitaeniorhynchus Giles, and Lutzia vorax Edwards. Forty blood-fed mosquitoes were collected and 95% of bloodmeals of Cx. pipiens pallens were avian-derived, whereas only mammalian bloodmeals were identified for Ae. albopictus. Plasmodium DNA was amplified from 65% (15/23) of blood-fed Cx. pipiens pallens and unfed females of Cx. pipiens pallens and Cx. pipiens form molestus with a minimum infection rate of 29.9 and 13.5, respectively. One unfed female of Lt. vorax was also positive for Plasmodium parasites. Five genetically distinct lineages of Plasmodium were identified, with 0.21 to 5.86% sequence divergence. Rinshi-8, the most prevalent lineage at our study site, was identical to the published sequence of Plasmodium relictum-P5.

This study was made to determine the effects of bloodmeal mass and oviparity in Aedes albopictus (Skuse) (Diptera: Culicidae) on continued host-seeking activity in female mosquitoes and efficacy of the repellent N,N-diethyl-3-methylbenzamide (DEET). There was a curvilinear relationship between bloodmeal mass in partially fed Ae. albopictus and host avidity with a threshold between 0.8 and 1.0 mg of ingested blood for reduced host seeking by female mosquitoes. Egg development and fecundity were related to bloodmeal mass, which also evoked significantly different mean host seeking rates in nulliparous and parous Ae. albopictus. The repellency of DEET to partially blood fed female mosquitoes depended on oviparity status and host avidity with repellent failure soonest in partially blood fed nullipars.

Host-seeking nymphal Amblyomma americanum (L.) (Acari: Ixodidae) were placed into heated water, and their survival or their torpidity was recorded as a function of exposure time. Exposures were determined that either kill the nymphs or affect their mobility. All nymphs died when exposed for a minute or more to a temperature >51°C. Nearly all nymphs remained motionless for a period of time when exposed for 3 min to a temperature >44°C.